1. Field of the Invention
The present invention relates to a shake correction mechanism adapted as an anti-shake mechanism of a lens barrel, which is equipped in an image sensing apparatus such as a digital camera and a camera phone, and to an image sensing apparatus provided with the shake correction mechanism.
2. Description of the Related Art
Various types of anti-shake mechanisms (shake correction mechanisms) are incorporated in digital cameras or like apparatuses to suppress photographing failure arising from hand shake of the user or the like. Heretofore, the following shake correction mechanisms have been put into practice. Japanese Unexamined Patent Publication No. HEI 7-274056 (hereinafter, called as “D1”) discloses an arrangement in which a lens barrel is pivotally supported by a so-called gimbal mechanism. Japanese Unexamined Patent Publication No. HEI 5-66444 (called as “D2”) discloses an arrangement in which a lens group disposed inside a lens barrel is driven on a plane perpendicular to the optical axis of the lens group in such a direction as to cancel camera shake. Japanese Unexamined Patent Publication No. 2003-110919 (called as “D3”) discloses an arrangement in which a solid-state image sensor such as a CCD sensor is driven on a plane perpendicular to the optical axis of a lens group provided in a lens barrel without driving the lens group.
Recently, miniaturization of image sensing apparatuses is a trend. As such a trend is widespread, the space available for the lens barrel is narrowed. Particularly, there is a strong demand for miniaturization of camera phones or like apparatuses. Naturally, miniaturization of a shake correction mechanism is demanded in the case where an anti-shake mechanism is mounted in such a miniaturized image sensing apparatus.
In the arrangement of D1 employing the gimbal mechanism, it is necessary to dispose a freely-rotatable joint or an equivalent member in two directions with respect to the lens barrel so as to pivotally support the lens barrel. Therefore, the size of the shake correction mechanism is inevitably increased. If miniaturization is attempted in the arrangement of D1, rigidity of bearing portions of the rotary joints or the like may not be secured. In the arrangement of D2 in which the lens group is driven on the plane perpendicular to the optical axis, two stages for moving the lens in parallel are required, which obstructs the miniaturization. Furthermore, this arrangement entails minimizing sensitivity of optical performance such as parallel displacement or tilt displacement of the lens group, which deprives the camera of flexibility in optical designing. Thereby, the size of the lens barrel may be increased, and sufficient anti-shake performance is not obtainable. In the arrangement of D3 in which the solid-state image sensor itself is driven, two stages for driving the image sensor in parallel are required, as well as the arrangement of D2, which also obstructs the miniaturization.